Amid a recently increasing interest in a security technique for personal possessions and information, with an aim to enhance security and convenience at, for example, office buildings in particular, attention has been drawn to a biometric authentication technique including a fingerprint, iris, vein, voice, and the like as a personal authentication technique with superior confidentiality and less risk of fraudulent use due to theft or loss as well as an authentication medium such as a non-contact card. Above all, finger vein authentication allowing authentication only by irradiating a finger with near-infrared rays causes less psychological resistance, uses internal information of a living body, and thus, is superior in resistance to forgery.
As a related art in the present technical field, there is JP 2008-79629 A (PTL 1). Described in this publication is a clause stating, “a finger placing section that supports and positions a finger to be authenticated in contact with a pad side part thereof is formed in a case, which has a configuration where parts corresponding to upper and bottom sides and left and right sides of the finger to be authenticated are closed, parts corresponding to front and back sides thereof are open, and an imaging range of an imaging means such as an imaging element is formed inside the parts corresponding to the left and right sides thereof” (see ABSTRACT).